Hi.
I have see a courious problems....i have tryed to send mail from webmail with squirrel mail from email hosted on the same server but is a different domain, to domain which point to google mail server.
When send this mail....is sended whit mail postmaster@example.com and not postmaster@mydomain.com!!!!!!
I have see in the virtual user table and not exist any instance whit example.com!!

hi!
i have solved this problem.....(of example.com! )
but the problem of postfix remain:

The Postfix program

<admin@mysite.com>: mail for mysite.com loops back to
myself
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I have tryed to add mysite.com to local host name but when send email receive error message: user not in virtual table...and reject my request